1. Field of the Invention
This invention relates to technologies and business processes for dynamic cellular phone rate pricing based on cellular traffic patterns, and especially to methods and systems which encourage consumer behavior changes which optimize loading of equipment and return on investment for cellular infrastructure.
2. Description of the Related Art
Millions of people around the world use cellular phones as a means to talk with one and another and to access to various sources of information. With a cellular telephone, users are able to use an incredible array of features and functions such as storing contact information, making to-do task lists, sending or receiving text or voice messages and being able to connect to the Internet.
Regardless on the makes and models of cellular phones being supplied to the marketplace, cellular phone companies actively offer different rate plans to attract and retain new and existing customers. Various rate plans include, but are not limited to, prepaid, area-limited and either one or two-tiers of time-based services such as “peak,” “off-peak,” and “nights and weekends.” The last being the most commonly used in today's marketplace.
A cell phone is actually a sophisticated radio that functions along with cell phone towers. The battery-powered, portable devices which perform wireless networking for voice and/or data communications as all or part of their functionality are well known in the art, including but not limited to:                (a) cellular telephones;        (b) wireless web browsers;        (c) cordless telephones and cordless small office/home office (“SOHO”) telephone switch systems;        (d) laptop computers, palm top computers and personal digital assistants (“PDA”) equipped with wireless local area network (“LAN”) or cellular data interface cards; and        (e) one-way, two-way, text and voice pagers and terminal devices.        
For the remainder of this description, we will refer primarily to cellular telephone examples and implementations to be representative of a range of these devices. Certain terms from cellular telephone parlance are analogous in functionality to terms from other networking technologies, such as Personal Communications Systems (“PCS”) towers being similar to “base stations” or wireless access points. It will be readily recognized by those skilled in the art, however, that the problems and the invention presented herein are common to all the various wireless network battery-powered devices as previously exemplified.
A key aspect of each cellular system is the division of a service area into small “cells”, each cell being served by a single tower, access point or base station. Turning to FIG. 1, two “cells” (10, 11) are shown geographically adjacent to each other, each cell having a “tower” (12, 13) located at its center. Typically, cells are considered to be of hexagonal shapes (15, 17) for network planning and management purposes in PCS architecture, but in reality, the signals from the towers propagate equally well for a generally circular area (14, 16) of coverage. This often produces areas of coverage overlap (18) between adjacent cells. In practice, a cellular system (19) comprises multiple cells in a honeycomb arrangement, but only two adjacent cells are shown here for ease of understanding.
When a terminal device such as PCS handset or wireless web browser is at a position P1 outside of reception range (14, 16) of a tower within the system, the device will be unable to perform its functions such as making or receiving telephone calls, performing data communications, receiving text messages, etc. Most systems will continuously “search” for a tower signal, performing some type of protocol to make contact with one or more towers which may be within reception range.
This process of searching may simply include measuring a signal strength on a frequency and/or channel from the tower, or may be more active such as sending or transmitting a signal from the device's transmitter to initiate a contact with an in-range tower. While the former approach will consume some power for the search, the latter almost always consumes even more power as transmission of signals is usually a more power intensive operation than simply receiving a signal.
As a device reaches or travels to a position P2 in the “fringe” area of coverage for a tower, it may detect a usable signal strength from the tower (12) within its reception range, and/or may be able to effectively transmit a code, registration or other signal to the tower (12). At this position, the device is technically within the tower's cell (10).
The “logging in” or “registration” process as a device enters a tower's cell varies between different wireless technologies. For example, the registration process employed by PCS systems is different than the registration process used by its predecessor “analog” (e.g. “AMPS”) cellular system, and both are very different than the registration process employed by wireless data networking technologies such as BlueTooth, IEEE 802.11b, Motorola's Ricochet network, and two-way pager networks, etc. For illustrative purposes, however, we now present a brief overview of the PCS registration process.
Cell phones and base stations use low-power transmitters, so that the same frequencies can be reused in non-adjacent cells which allows millions of people to use call phones simultaneously. Each city comprises, for example, of hundreds of towers while each carrier in each city runs one central office called Mobile Telephone Switching Office (“MTSO”), which handles all of the phone connections to the normal land-based phone system and controls all of the base stations in the region. A cell phone is composed of three unique codes that help carriers identify each gadget and facilitate call transmission. Each cell phone has its unique 32-bit number programmed into the phone when it is manufactured called Electronic Serial Number (“ESN”). Once service is activated, the cell phone will have the 10-digit phone number called the Mobile Identification Number (“MIN”) and an unique 5-digit number that assigns to each carrier (e.g. Sprint, MCI, AT&T, Verizon, etc.) by the Federal Commission (“FCC”) called the System Indentication Code (“SID”) programmed.
When a cell phone is first powered up, it “listens” for an SID on the control channel. The phone and base station uses the control channel, a predetermined special frequency, to talk to one another about things like call set-up and channel changing. If the phone cannot find any control channel to listen to, then it knows that it is out of range and displays a “No Service” indicator or “Out of Range” message. When the phone receives the SID, it compares it to the SID programmed into the phone. If authentication is successful, then the phone is communicating with its home system. The phone transmits a registration request along with the SID, which is received by one or more towers within range while the MTSO keeps track of your phone's location in a database. For example, in FIG. 1, if the handset is in position P2, only one tower (12) may receive the registration request. If the handset is in position P4, however, when it is powered ON initially, it may be within the overlap of multiple cells, and the registration request may be received by multiple towers (12, 13), or may be directed to the tower for which the strongest signal strength is detected.
This allows the MTSO to know which cell grid the user is currently in so it knows when to ring the phone. When the MTSO receives a call, it searches the database to see which cell the user is in. The MTSO selects a frequency pair that the phone will use in the cell grid to take the call. By using the control channel, the MTSO communicates with the phone to inform which frequencies to use. Once the user's phone switches on those frequencies, the call will be connected.
Many wireless networked systems are designed to handle providing continuous service as a unit travels from one cell to another, while other technologies do not provide this functionality. For example, a PCS telephone is expected to be used in a moving vehicle or while walking, and as such, the PCS system specifications and design include protocols and schemes for “hand off” of service to a handset from one cell tower to another. So, for example, as a handset moves from position P3 to position P4, and then to position P5, the handset may initially be served by a first tower (12), and then be handed off to another tower (13) according to signal strength criteria and channel availability in each area of coverage (14, 15).
The cellular base station constantly notes a user's signal strength is diminishing as the user moves toward the edge of the base cell grid. At the same time, the base station in the cell the user is moving toward is aware of the increasing phone signal strength by listening and measuring signal strength on all frequencies. Then, the two base stations coordinates with each other through the MTSO, and at some point, your phone gets a signal via control channel to change frequencies. This hand off switches the user's phone to the new cell. If the SID on the control channel does not match the SID programmed on the mobile device, then the phone knows that it is roaming. The local MTSO of the cell where the user is roaming will contact the MTSO of the home system to verify its database that the phone's SID is valid. Once verification occurs, the local MTSO will track roaming usage as the phone moves through its cell.
Turning to FIG. 2, a larger portion of a cellular network (24) is illustrated, to show how a terminal or handset may traverse multiple positions P1, P2, P3, P4, P5, P6, P7, and P8, starting outside a network, entering the fringe of the network, passing through and being served by multiple cells (20, 21), and finally passing through the fringe and out of the network. Certain cells (23, 22) may never provide service to the handset based upon its position and proximity to other, closer towers.
Turning to FIG. 3, a generalized architecture (40) of these types of hardware platforms is depicted. Although each actual device available on the market may vary in detail from this depiction, the general functionality and capabilities of each platform fit within the general view of this figure. Each system typically includes all or some of the following functions:                (41) a microprocessor, microcontroller, or control logic for implementing the logical processes of the unit;        (42) one or more application specific integrated circuits (“ASIC”) for voice compression, decompression, protocols, error checking/correction, security, encryption/decryption, and radio signal modulation/demodulation;        (43) an audio microphone and speaker or earphone for audible interfacing with the user;        (44) a radio frequency (“RF”) frontend including intermediate frequency stages, and an antenna (45) for receiving and transmitting RF signals (401) from and to a tower, base station, or wireless access point (404);        (46) one or more memory devices and types including some or all of Random Access Memory, FLASH Read Only Memory, battery-backed memory, and Read Only Memory, with one or more memory expansion slots (47) in some cases;        (48) a display such as an liquid crystal display (LCD), color TFT, or cathode ray tube (CRT) display, often coupled with a touch screen sensor for receiving user input and selections, typically provided with a keypad or keyboard or other special buttons for receiving user input and selections;        (49) often several external I/O connectors for battery chargers, external speakers and microphones, expansion keyboards and displays;        (400) often additional data interfaces such as IrDA or PCMCIA slots for receiving add-on hardware, interfaces, program packs, or software; and        (403) a clock, timer and/or calendar for keeping time in units such as seconds, minutes, hours, days, months and years.        
More advanced wireless network devices may include a location technology in detail such as a GPS receiver or E911 capability (402).
As mentioned before, carriers offer a wide range of cellular rate plans to users. Most services providers offer three different levels of coverage such as local, regional and national, generally illustrated in FIG. 4. Local coverage (451) usually limits service area to a particular metropolitan area. The plan typically provides more minutes per month than other coverage plans for local call, and calls in extended (453) area may be higher. Calls originated from a roaming (452) area may incur charges from other carriers, as well. Other regions (450) may not have coverage at all.
Some carriers now offer unlimited local airtime to lure customers. Many recoup their costs by charging more per minute for roaming and by tacking on a per-minute airtime charge for calls made outside the local area.
Regional coverage enlarges the service area to include the entire state as well as selected surrounding ones. For example, local coverage in a southeastern U.S. plan might include Alabama, Arkansas, Florida, Georgia, Kentucky, Louisiana, Mississippi, North Carolina, South Carolina, Virginia and Tennessee. Calls within and between any of these states don't have any associated roaming and long distance charges. These plans cost more and also give you fewer airtime minutes per month than similarly priced local plans. In addition, if one uses more minutes than provided within the plan, a surcharge will apply for extra usage.
National coverage (453) is often a flat-rate national plan, that is available anywhere in the United States where the carrier offers service with no roaming or long distance charges. Most carriers reach close to 95 percent of the United States with a combination of analog and digital service. National plans offer even less airtime per month than regional plans and are usually the most expensive option.
The very popular service plan most consumers use today is the fixed monthly rate pricing that buys a certain number of airtime minutes for both peak and off-peak hours and other extra features for add-on such as text messaging, call waiting and Internet browsing. After a customer passes a credit check, carriers usually recommend signing a contract for a certain period of time from eleven months to three years. The carrier, in return, offers free or steeply discounted phones, accessories and even pricing plans for the duration. Like any other contract with its provisions, should the user decide to cancel before the term of the contract, a steep penalty charge is incurred.
Turning to FIG. 5, a typical monthly rate plan is shown in table form. The rate table (50) includes a number of “types” of services, such as minutes of voice usage in the local calling area, in the rows (51). The pricing or allowed consumption varies based on several characteristics such as the coverage area (51), type of service (52), number of minutes included based on minute types such as daytime (53), nighttime (54), weekend (55) or anytime (56). So, for each entry in the table, a carrier may define a maximum number of minutes included in the rate plan, and may define a surcharge for each minute of that type of service over the prepaid amount in a period of time such as a month.
For example, at $39.99 a month, hypothetically called “MetroTalker”, a consumer can have the standard local voice 3000 minutes which consists of 500 daytime minutes (LV-Day) from 7 AM to 7 PM on weekdays, 2000 nights (LV-Night) after 7 PM on weekdays, 500 weekends (LV-Weekend) and zero anytime (LV-Anytime) minutes. For any additional minutes use, depending on time period, a surcharge is incurred on a per minute basis. For example, day overage charge may be 14 cents per minute, and night or weekend overcharge may be 8 cents per minute. So, the entries in the table (50) for this rate plan “MetroTalker” would be:                LV-Day=(500, 14)        LV-Night=(2000, 8)        LV-Weekend=(500, 8)        LV-Anytime=(0, 0)        
Similarly, extended area and roaming minute maximums and overcharges can be defined for voice services, as well as defined for other types of calls (e.g. data, pictures, text messaging, web browsing).
It is important to note, however, that these rate plans take into account the time of day and week of the service usage (e.g. night vs. day, weekend vs. weekday), the type of usage (e.g. voice, data, browsing, etc.), and the service region or area from which the call originates, wherein each region or area contains multiple cells (e.g. multiple towers).
Turning to FIG. 6, a generalization of the present-day billing reconciliation process (60) is shown. The mobile device (61) makes a call through a tower (62), and its service usage data is recorded by a base station (63). The base station (63), also captures the time and day of the usage (64). The base station is not aware of specific rate plans the mobile device is assigned because it can be a MTSO of another carrier.
Usage records (65, 65′) are transferred to a billing server (66) for accounting processing. The billing server consolidates the usage records, verifies them against rate plans (68) and gathers customer profile information (67) to generate customer monthly invoice (69). The billing plan is either time-based or rate plan based.
It is important to note, again, that the invoice to the customer contains calculations and charges based upon the minutes of service used during a billing cycle, when those minutes were used (e.g. time, day of week), and the region from which the service originated or was consumed (e.g. home, extended, roaming, etc.). There is no calculation of the charges due to the customer based upon any other factors typically.
As such, cellular phone carriers offer fixed rate plans which do not take into account the geographically based costs associated with cellular services within regions of service. Geographic costs associated with cellular telephone usage include the cost of land lease, towers, switches, and other associated processing equipment, the human costs of cellular company employees, and the costs associated with service levels.
For example, consider a local region that has 67 towers or 67 cells in it. Each of those towers has its own set of costs: cost of leasing the land on which the tower is placed, cost of operating and maintaining the equipment in the tower and base station, etc. Some towers are owned by the service provider, while others are leased from other owners.
For instance, in a low usage cell, underutilized equipment is a cost, and inversely, in an overly busy area, excessive usage may drive the need for additional bandwidth. Similarly, newer towers may be more costly than older, depreciated towers. But, the fees collected from the users for using these different towers or cells within a rate region are the same. For example, let's assume a prepaid cellular plan provides for debiting a user's account balance at the rate of 9 cents per minute for calls made from home region. Also assume, again, that there are 67 towers in the home region. Further assume that cell #19 is the newest cell, and has a cost of operation of 15 cents per minute, and that cell #45 is the oldest cell and has a cost of operation of 2 cents per minute.
If the user makes a call from cell #19, the revenue from the call is 9 cents per minute, even though the cost to operate the cell is 15 cents per minute. So, calls handled by this cell under this rate plan actually lose 6 cents per minute. However, calls originating from cell #45 produce a positive revenue of 7 cents per minute.
To be profitable, the sum total of all of the cellular operational costs in a calling region must not exceed the sum total of the revenue from service consumed by all users on all rate plans within that region.
Often times, though, the newer and more expensive to operate cells are also the most heavily used. Consider a growing metropolitan area in which a downtown area is experiencing a business boom. This means that more towers will be needed in the downtown area. But, these new towers fall within the existing “local” region of rate plans, and as such, the revenue from their usage will be the same as that from the existing towers in the local region. Thus, to meet increasing demand and traffic, carriers are often forced to install new equipment, which often results in a negative revenue generation.
Carriers currently have no means for redirecting calls and services from a higher cost cell to a lower cost cell, especially for cells within the same rate region. Therefore, there exists a need in the art for a method which utilizes service consumption to modify consumer behavior encouraged by geographical-based pricing advantages related to cellular operational characteristics within a rate plan region.
It would be difficult to publish a map of cells within regions to users, especially considering the overlap of coverage between adjacent cells. Radio range coverage not only varies based upon geographical conditions (e.g. hill sides, buildings, etc.), but also upon varying weather conditions.
Additionally, rate plans are already complicated and many consumers complain about their inability to understand the pricing schemes already employed. Publishing a rate plan which breaks the fees into cells within regions would further exasperate this problem.
Further, publishing rate plans and brochures is costly, and therefore is only performed periodically by cell phone companies. However, changes to usage and costs of individual cells is relatively dynamic. It would not be practical, however, to publish a new rate plan brochure or guide daily or weekly in order to update costs of usage by cell.
In some jurisdictions, rate plans must be approved by a regulatory body or agency, which can be costly, timely and laborious to update. For this reason as well, dynamically changing a rate plan is not desirable.
Therefore, there additionally exists a need in the art for a new system and method for adapting service usage among multiple cells within a rate plan region without requiring new rate plans to be published, documented, authorized, approved, comprehended or adopted.